Various seat shock absorbers have been used heretofore. For example, a striking energy generated in the event of failure in landing of an airplane is mostly absorbed by a shock absorber provided on the airplane body side. In the event of automobile collision, the resulting striking energy is absorbed by a shock absorber provided between a bumper and the chassis.
In a landing failure accident of an airplane or in an automobile collision accident, however, there sometimes is generated an impact load exceeding the impact absorbing ability of a shock absorber, and in this case a too large impact load is applied to passengers. As the seat particularly in aircraft, in order to absorb such striking energy, there has been used a seat having a striking energy absorbing member constituted by a cylindrical body of a synthetic resin-carbon fiber composite and functioning to absorb energy through a crushing load of the said member obtained by suitable arrangement and proportion of the carbon fibers used.
In the above striking energy absorbing member in such conventional seat, however, it is difficult to determine the structure of the synthetic resin - carbon fiber composite in a physical-propertywise manner and there arise variations in the product accuracy so it is difficult to make production control. Consequently, it is impossible to stably ensure a constant amount of energy absorbed. Further, most of the components, including the seat leg structure, are formed using undeformable materials, so coupled with structural characteristics of the foregoing striking energy absorbing member, it is impossible to take a sufficient seat moving stroke for the absorption of striking energy.
The present invention has solved the above-mentioned problems and it is the object thereof to provide a striking energy absorbing seat leg structure which is simple and capable of forming a sufficient stroke for the absorption of striking energy, affording a stable amount of energy absorbed, and contributing to the reduction in weight of seats particularly in an airplane.